Embodied cognition theorists suggest that cognition is bodily based and that the brain developed due to interaction with the environment, and thus evolved to facilitate sensorimotor processing. As such, one goal of embodied cognition research is to determine how the interaction between the body and the environment affects the storage and processing of semantic information. Recent neuroimaging research has shown that the sensorimotor and premotor cortices are activated somatotopically when responding to action-related stimuli. In addition, behavioural research has provided evidence in support of the theory of embodied cognition, in that the sensorimotor properties of a stimulus have been shown to affect performance on language tasks. The goal of the current research was to provide a novel and comprehensive examination of the theory of embodied cognition through the combination of multiple experimental paradigms.
Several functional magnetic resonance imaging and behavioural experiments on healthy participants were carried out, as well as a behavioural study of two individuals who have undergone either a left or right hemispherectomy. The results from the functional neuroimaging experiments demonstrated that there are common regions of activation between motor movements and semantic processing, whereby sensorimotor and premotor regions that are responsible for arm and leg motor movements are also recruited when responding to arm- and leg-related action semantic knowledge. Thus these results are consistent with the theory of embodied cognition, suggesting that the motor system is involved in the processing of action-related semantic information. The behavioural results were also consistent with previous research showing that pictures have privileged access to action-related semantic knowledge. Additionally, the behavioural results with hemispherectomy patients provided evidence regarding the necessity versus sufficiency of the left and right hemispheres when responding to arm- and leg-related semantic knowledge. Finally, given that words rated as higher in body-object interaction were responded to faster than words rated as lower in body-object interaction, these results show evidence that language processing is grounded in bodily interaction and sensorimotor processing. Together, the results further advance the theory of embodied cognition, and moreover, provide an in-depth analysis of how arm- and leg-related stimuli are processed dependent upon presentation format.